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  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 82 (1985), S. 161-169 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The 3D classical trajectory surface hopping (TSH) method has been applied in a "model'' study of factors governing nonadiabatic reaction, A+BC→AB+C* and →AB+C. In the diabatic approximation the potential-energy surfaces (pes) were a LEPS surface for F+H2 (→AB+C*) and a repulsive pes Vrep (→AB+C). These intersected in the exit valley to give an early or a late seam (E or L, perpendicular to the exit valley). The splitting at the avoided crossing 2ε was adjusted to ε=1.26 or 5.02 kcal/mol. The ratio of reactive cross sections onto the upper and lower adiabatic pes ρ* was investigated for mass combinations H+HL, L+HL, L+HH, and H+LL with E and L seams, and for small and large ε. The effect on ρ* of reapportioning a constant total energy (ETOT=13.84 kcal/mol) between reagent translation T and vibration V was examined for these 16 cases. Since the velocity in the coordinate of separation increased with increased T (yielding increased product translation; ΔT→ΔT') ρ* also tended to increase with T. The extreme mass combinations H+HL and L+HH exhibited modified ρ* due to markedly differing widths in the entry and exit valley. The strongly skewed pes for H+LL led to multiple crossing of the seam which reduced ρ*. For other mass combinations ρ* was reduced by the inability of the low T' component of the product to hop across the 2ε gap. In all cases ρ* was an index of the local dynamics at the seam, and hence shed light on the intermediate motions en route to the asymptotic outcome V', R', T'.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 82 (1985), S. 170-174 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The same model potentials as were used in part I (preceding paper) have been employed in a study of the effect of nonadiabatic exchange reaction on product vibrational energy distributions. The exit-valley seam at which hopping from a lower (L) to an upper (U) potential energy surface (pes) occurred could be altered from early (E) to late (L), and from inner (I) to outer (O). The splitting 2ε, between the pes could be made small or large. The computations involved trajectory surface hopping for the mass-combination light plus heavy light (L+HL), in three dimensions (3D). The effects on P(v′) of alterations in reagent energy, and changes in the pes, could be understood in terms of the local motion, part way through the reactive encounter in the configurations at which the seam was encountered. The seam was effective as a "filter'' favoring reaction into low v′U', , following the hop to the upper pes, particularly if ε was large, since the seam allowed trajectories with higher speed along the exit valley to pass onto the U surface and these correlated with low vU. Surface hopping strongly favored low v′U if the seam location was of the "inner'' type (I), and favored high vU if the seam was an "outer'' one (O), since the reaction intermediate leading to the upper surface was a compressed one in the former case, and an extended one in the latter.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 98 (1994), S. 8600-8605 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 88 (1984), S. 4064-4068 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 13 (1981), S. 845-854 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A preliminary report is given of relative reactive cross sections for four abstraction reactions H + H′Br ← HH′ + Br with attacking atom (A) H or D, and atom under attack (B) H or D. The pattern of reactive cross sections, as obtained in a crossed molecular beam experiment at a collision energy ET = 7 kcal/mol, indicates Sr(D,H) ≤ Sr(D,D) 〉 Sr(H,H) 〉 Sr(H,D). The atoms in parentheses are A and B. We describe a three-dimensional classical trajectory (CT) study on a potential-energy surface proposed in 1969 by Parr and Kuppermann (PK); the CT results are in fair accord with experiment. It is suggested that (D,H) has the largest cross section because it exhibits the most favorable relative timing of A approach to BC rotation. On the basis of CT it appears that the same sequence of cross sections and the same rationale may be applied to the exchange reactions H + BrH′ ← HBr + H′.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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